Formaldehyde in rain water in Mexico City atmosphere

Abstract

Measurements of formaldehyde in rain water were perfonned at the National University of Mexico during the rainy seasons of 1981 and 1982. A total of 71 samples from storms and prolonged rains were analyzed. The results obtained throughout this study gave an average of 0.479 ± 0.19 mg/1, much higher than those reported in rain water by different authors formaritime and clean coastal air. The statistical program "cross tabulation" applied to CH₂O concentrations, indicated a linear correlation only between the CH₂O concentrations, sunshine hours and the time when precipitation began. The high CH₂O values found in rain water indicated a much greater source than that provided by the methane oxidation. Motor vehicles emissions and the huge combustion of fuel oil are the obvious candidates for the additional.CH₂O sources in the atmosphere of Mexico City.